/**
 * WooCommerce Cart/Checkout Blocks.
 *
 * The block checkout is React and its address inputs are controlled: a value
 * written into the DOM from outside is discarded on the next render, and the
 * `wc/store/cart` data store — which is what the order is actually built from —
 * never hears about it. So nothing here touches a field. The postcode is read
 * from the data store, and the resolved address is written back through the
 * store's own `setShippingAddress` / `setBillingAddress` actions, which is the
 * documented extension point. React then re-renders the inputs itself.
 *
 * Only the request layer is shared with the classic integration:
 * `CepisAutofill.lookup` is the widget's HTTP client without its DOM half —
 * same cache, same error codes, same handling of 400, 404, 429 and 5xx.
 *
 * @module
 */

(function () {
  var config = window.cepisWooCommerce;
  var data = window.wp && window.wp.data;

  if (!config || !config.fields || !window.CepisAutofill || !data || !data.select) {
    return;
  }

  var CART = "wc/store/cart";
  var NOTICES = "core/notices";

  /**
   * Where a notice has to be rendered for the Checkout block to show it.
   */
  var NOTICE_CONTEXT = "wc/checkout";

  /**
   * One id, so a new failure replaces the previous message instead of stacking.
   */
  var NOTICE_ID = "cepis-woocommerce-lookup";

  var SECTIONS = {
    shipping: { address: "shippingAddress", write: "setShippingAddress" },
    billing: { address: "billingAddress", write: "setBillingAddress" },
  };

  var progress = {
    shipping: { cep: "", timer: 0, written: {} },
    billing: { cep: "", timer: 0, written: {} },
  };

  /**
   * The one field the shopper is never asked about.
   *
   * A street name is worth protecting — the shopper may know better than the
   * database. A state is not: the CEP decides it. WooCommerce also starts the
   * checkout with the store's own state already selected, which the `"auto"`
   * rule would read as the shopper's choice and never touch, quietly filing a
   * Rio address under São Paulo.
   */
  var ALWAYS = "uf";

  /**
   * Whether a field may be written.
   *
   * Mirrors the widget's `overwrite` option: `"auto"` protects anything the
   * shopper typed but replaces what a previous lookup wrote, so correcting the
   * street by hand survives the next CEP.
   *
   * @param {string} field The API's name for the field.
   * @param {string} current Value the store holds now.
   * @param {string|undefined} written Value this plugin last wrote there.
   * @returns {boolean}
   */
  function writable(field, current, written) {
    if (field === ALWAYS || config.overwrite === true) {
      return true;
    }
    if (current.trim() === "") {
      return true;
    }
    if (config.overwrite === false) {
      return false;
    }
    return written === current;
  }

  var pending = {};

  /**
   * Look a CEP up once, however many sections want it.
   *
   * With "use the same address for billing" on — the default — the shipping
   * and the billing observer see the same postcode land in the same tick. The
   * widget's own cache is only filled once a response is back, so without this
   * the store would send two identical requests for every CEP a shopper types.
   *
   * @param {string} digits The eight digits.
   * @returns {Promise<Record<string, any>>}
   */
  function resolve(digits) {
    if (!pending[digits]) {
      var forget = function () {
        delete pending[digits];
      };

      pending[digits] = window.CepisAutofill.lookup(digits, {
        baseUrl: config.baseUrl,
        timeoutMs: config.timeoutMs,
      });
      pending[digits].then(forget, forget);
    }

    return pending[digits];
  }

  /**
   * Show one message in the Checkout block's own notice area.
   *
   * @param {string} text Message, already translated.
   */
  function announce(text) {
    data.dispatch(NOTICES).createNotice("error", text, {
      id: NOTICE_ID,
      context: NOTICE_CONTEXT,
      isDismissible: true,
    });
  }

  /** Take the message away. */
  function silence() {
    data.dispatch(NOTICES).removeNotice(NOTICE_ID, NOTICE_CONTEXT);
  }

  /**
   * Say which municipality a CEP that does not exist would have been in.
   *
   * Replaces the notice already on screen — same id, so the block swaps the
   * text rather than stacking a second error. The failure is reported
   * immediately and refined a round trip later, because making the shopper wait
   * on a second request before being told anything at all is worse than the
   * message improving under them.
   *
   * Nothing here goes near `apply()`. A CEP the Correios do not have has no
   * address, and the municipality in a 404 is a guess about which digit went
   * wrong, not a place to ship to.
   *
   * @param {string} name Section name, `shipping` or `billing`.
   * @param {string} digits The CEP that was not found.
   * @param {string} shown The message already in the notice area.
   */
  function explain(name, digits, shown) {
    var helper = window.cepisWooCommerceFaixa;

    if (!helper) {
      return;
    }

    helper.message(digits, shown, function (message) {
      if (message !== shown && progress[name].cep === digits) {
        announce(message);
      }
    });
  }

  /**
   * Write a resolved address into the store.
   *
   * @param {string} name Section name, `shipping` or `billing`.
   * @param {Record<string, any>} address The API's answer.
   */
  function apply(name, address) {
    var customer = data.select(CART).getCustomerData();
    var current = (customer && customer[SECTIONS[name].address]) || {};
    var written = progress[name].written;
    var patch = {};
    var changed = false;

    Object.keys(config.fields).forEach(function (field) {
      var key = config.fields[field];
      var value = address[field];

      if (!key || typeof value !== "string" || value === "") {
        return;
      }

      var held = current[key] == null ? "" : String(current[key]);
      if (!writable(field, held, written[key])) {
        return;
      }

      patch[key] = value;
      written[key] = value;
      changed = true;
    });

    if (changed) {
      data.dispatch(CART)[SECTIONS[name].write](patch);
    }
  }

  /**
   * Resolve one CEP and write what comes back.
   *
   * @param {string} name Section name, `shipping` or `billing`.
   * @param {string} digits The eight digits.
   */
  function run(name, digits) {
    silence();

    resolve(digits).then(
      function (address) {
        if (progress[name].cep === digits) {
          apply(name, address);
        }
      },
      function (error) {
        if (progress[name].cep !== digits || error.code === "aborted") {
          return;
        }

        var shown = config.messages[error.code] || error.message;
        announce(shown);

        if (error.code === "not_found") {
          explain(name, digits, shown);
        }
      },
    );
  }

  /**
   * React to whatever the store now holds for one address.
   *
   * @param {string} name Section name, `shipping` or `billing`.
   * @param {Record<string, any>|undefined} address Address from the store.
   */
  function observe(name, address) {
    var seen = progress[name];

    if (!address || String(address.country || "") !== "BR") {
      return;
    }

    var digits = String(address.postcode || "").replace(/\D+/g, "");

    if (digits.length !== 8) {
      if (seen.cep !== "") {
        seen.cep = "";
        window.clearTimeout(seen.timer);
        silence();
      }
      return;
    }

    if (digits === seen.cep) {
      return;
    }

    seen.cep = digits;
    window.clearTimeout(seen.timer);
    seen.timer = window.setTimeout(function () {
      run(name, digits);
    }, config.debounceMs);
  }

  data.subscribe(function () {
    var store = data.select(CART);
    if (!store || typeof store.getCustomerData !== "function") {
      return;
    }

    var customer = store.getCustomerData();
    if (!customer) {
      return;
    }

    Object.keys(SECTIONS).forEach(function (name) {
      observe(name, customer[SECTIONS[name].address]);
    });
  }, CART);
})();